Aerodynamic — well-suited for flight.
Aerodynamics — the study of the forces acting on objects moving through air.
Airfoil — a surface, such as a wing, designed to produce lift.
Archaeopteryx — a fossil bird from the late Jurassic having reptilian features such as teeth, as well as avian features such as feathers.
Asymmetrical — not symmetrical; one side different than the other.
Biomechanics — examining the structure and function of living organisms as one would a machine—how things work together.
Bipedal — walking on two legs.
Bipedalism — describing an animal that typically walks on two legs.
Brooding — sitting as a bird over a nest.
Cladogram — a branching diagram indicating evolutionary relationships.
Clavicle — the collarbone.
Contour feathers — strong feathers with rachis providing a streamlined effect. Often colored for identification purposes.
Deinonychus — an active, agile theropod dinosaur.
Dichotomy — a division into two parts or choices.
Downy feathers — loose, fibrous feathers with no central support. Used for insulation.
Drag — air resistance, a force that opposes forward movement.
Furcula — the fused clavicles in theropods. Also called a wishbone.
Histology — the study of the microscopic structure of tissues.
Hypothesis — a statement suggesting an explanation for an observation.
Inference — a logical assumption based upon the evidence at hand.
Lift — one of two forces (along with thrust) generated to overcome weight and drag. Caused by the difference in pressure above and below a surface such as a wing.
Lineage — any continuous line of descent; those organisms connected by heredity from ancestor to descendent.
Maniraptorans — a group of dinosaurs characterized by very long arms, hands that are longer than their feet and an unusual wrist bone.
Oviraptor — a misnamed theropod! The name means “egg snatcher” but this dinosaur was actually tending to its own eggs, not feeding on those of another.
Powered flight — flight requiring a source of power to attain speed, as opposed to gliding.
Pterosaur — an extinct flying reptile.
Rachis — a strengthening support running up the center of some types of feathers.
Relative length — one length compared to another.
Saurischians — a group of dinosaurs with long, flexible necks, a large curved claw on the thumb and a second finger that is longer than the others. The group includes Coelophysis, Velociraptor, Archaeopteryx, and living birds among others.
Sedimentology — the study of the deposition of sediments.
Semilunate bone — a half-moon shaped bone in the wrist of birds that allows increased motion.
Semiplume feathers — insulating feathers with a strengthening support, called a rachis.
Sternum — a flat bone in the chest region, attached to the clavicles. Also known as the breastbone.
Thermoregulation — maintaining body temperature at a constant level through heat production, heat transport, etc.
Theropods — a group of bipedal, carnivorous dinosaurs that have a reduced number of fingers, an enlarged pelvis, a flexible lower jaw, and a head that has a wide range of motion around the neck joint.
Thrust — one of two forces (along with lift) generated to overcome weight and drag.